1. Field of the Invention
The present invention relates to an atomic force microscopy for measuring the configuration of a surface using extreme weak atomic force affecting between surface atoms and approaching probe atoms, a method of measuring surface configuration by using the microscopy, and to a method of producing magnetic recording medium.
2. Description of the Related Art
Recently, atomic force microscopy (often referred to as AFM) is commercially available which can observe very fine surface configuration with high fidelity. The principle of such microscopy is to observe the surface configuration at atomic size by detecting very weak atomic force affecting between the atoms on the surface with the approaching atoms of a probe to position the height (Z-axis position) of the probe to a predetermined value, in order to plot the Z-axis position at each location when scanning on an X-Y-axis micro-motion stage, as disclosed in for example Japanese Patent Laid-Open No. Hei 5-164514, Japanese Patent Laid-Open No. Hei 6-88723, and Japanese Patent Laid-Open No. Hei 7-325090.
The probe for the atomic force microscopy in the Related Art was made in general of such material as silicone, as described in, for example, Japanese Patent Laid-Open No. Hei 8-193941, and Japanese Patent Laid-Open No. Hei 10-90287.
Magnetic disks in the Related Art, on the other hand, were made by forming non-magnetic base film, magnetic film, protective film on a substrate and depositing thereon liquid lubricant. The liquid lubricant was applied in order to reduce the wear when a magnetic recording head is contacted with the magnetic disk. The wear will be increased if the liquid lubricant film is thinner layer, while on the other hand the magnetic recording head will be adhered if the lubricant film is thick layer to make such troubles as the magnetic disk device will not start up. In Japanese Patent Laid-Open No. Hei 7-192255 a method of producing magnetic disks and a method of evaluating the disks by measuring the average thickness of the lubricant film by FTIR (Fourier Transform Infra-Red spectrophotometry) as well as by measuring the conditions of coating by X-ray photo-electronic spectrometry in order for the lubricant to be coated in dots.
Since the atomic force microscopes in the Related Art as described above has in general large surface energy in the probe. If a trace of soft fouling such as oil is adhered onto the body surface, the soft fouling will adhere to the probe which in turn drags the soft fouling, resulting in a preventing the measuring of the configuration of surface.
In addition, the conventional method of producing a magnetic disk as described above has another problem in that it is difficult to obtain a magnetic disk with the lubricant characteristics well controlled by the measurement in short period of time. It may be thus difficult to sufficiently control the lubricant characteristics by using the measurements, because FTIR measurement measures and evaluates the average thickness of film. The X-ray photoelectronic spectrometry has disadvantages that, because the measurement of specimen is performed in a vacuum environment, the measurement requires time to make the vacuum environment, thus it is difficult to quickly measure the specimen. The X-ray photoelectronic spectrometry measurement has also disadvantages that it may erroneously evaluate the specimen because the dot-pattern distribution of lubricant is assumed to be equivalent and the same thickness of dot-pattern lubricant in every location. More specifically, in the state-of-the-art magnetic disks the flying height of the magnetic recording heads over the surface has been gradually decreased to about 25 nm due to the rushed increase of recording density of recent years. Thus there are needs for observing the conditions of fine lubricant film of less than 10 nm adhered onto the surface of magnetic disks, since the conventional method of producing magnetic disks as above lacks the capability to sufficiently follow the recent progress of magnetic disk as describe above.